"I really don't know how I even reached the final ... it would have really been the end of a fairytale, a horrible dream, if I'd won gold," Efimova said to The Associated Press after the race, her face red from crying. "But that was all I could do right now."

King, a 19-year-old student at Indiana University, is in her first Olympics.

"It just proves you can compete clean and still come out on top with all the hard work you put in behind the scenes, behind the meet, at practice and weight sessions," King told the AP. "There is a way to become the best and do it the right way."

Before King and Efimova faced off, Ryan Murphy set an Olympic record and won the United States' third swimming gold medal in Rio by taking the 100-meter backstroke on Monday night in 51.97 seconds.

Xu Jiayu of China was silver and David Plummer beat out Australia's Mitchell Larkin for bronze by .03 seconds.

Minutes earlier, Kathleen Baker won a silver medal in the 100-meter backstroke shortly after Conor Dwyer won a bronze for the United States in the 200 freestyle, adding to the USA's swimming medal haul on a night its biggest stars were in semifinals.